Reflux betyr tilbakeløp, tilbakestrømning, tilbakeløp stc., men kan også bety flo (flo og fjære - høyvann og lavvann). En reflux valve er for eksempel en tilbakeslagsventil.
The definition in Englsih, related to chemistry is:
Reflux: the liquid condensed from the rising vapor which returns to the pot flask.
The expression is also used in distilling processes - by heating the liquid it will vaporize into gas/steam and by cooling down to liquid and going back to the pot, it will reflux. I think that's what you're looking for? The Norwegian term for this reverse process (equal to condensing - "kondensering", the verb "kondensere") is according to my dictionary (ordnett.no) tilbakestrøming. However, one of the links below, from a university paper calls the process "refluks" - the verb would probably be "refluksere"

That's what I think a Monday morning in Norway :)

I would need more context to give a definite answer, but it seems like some liquid is heated up to a point where it starts flowing in the opposite direction?